1. Field of the Invention
This invention relates generally to magnetic disk storage systems, and more particularly, to a head suspension assembly for use in a magnetic disk storage system.
2. Description of Related Art
Magnetic disk drives are information storage devices that utilize at least one rotatable magnetic media disk having concentric data tracks defined for storing data, a magnetic recording head or transducer for reading data from and/or writing data to the various data tracks, a slider for supporting the transducer in proximity to the data-tracks typically in a flying mode above the storage media, a suspension assembly for resiliently supporting the slider and the transducer over the data tracks, and a positioning actuator coupled to the transducer/slider/suspension combination for moving the transducer across the media to the desired data track and for maintaining the transducer over the data track center line during a read or a write operation. The magnetic media disk or disks in the disk drive are mounted to a spindle. The spindle is attached to a spindle motor, which rotates the spindle and the disks to provide read/write access to the various portions on the concentric tracks on the disks.
One type of suspension is an integrated lead suspension assembly that includes a load beam, a flexure, and a mount plate. The flexure assembly is supported at its forward portion on a gimbal for allowing gimballing of the slider/magnetic head combination, and mounts at its rearward portion to the load beam. The actuator shifts the load beam generally radially across the disk to carry the head to all desired portions of the disk. The main function of a load beam is to suspend the flexure along with a slider/magnetic head assembly at a desired position and at the same time apply pre-load to the head assembly. The pre-load is typically exerted by the rearward spring area portion of the load beam. The flexure assembly may include an integrated assembly of a layer of flexible metal, and electrical traces separated from the metal layer by an insulation layer.
The prior art integrated lead suspension assembly has a number of drawbacks. Prior art shows different methods of bonding of the electrical leads to the slider on the flexure assembly. Ultrasonic bonding methods involve clamping on the slider through the load beam, which requires a wider load beam tip to facilitate a clamping means (e.g., see U.S. Pat. No. 5,892,637). However, the external excitation acting upon the wide load beam results in torsional (off track) and in-plane bending modes that are at lower resonance frequencies during operation of the disk drive, which are undesirable as they affect the dynamic performance of the drive. Other clamping approach permits narrower load beam tip, but such load beam structures exclude a lift tab for interacting with a ramp for head loading and unloading (e.g., see U.S. Pat. No. 6,021,022).
Prior art integrated lead suspensions include a limiter for limiting the separation of the flexure from the load beam during unload operation of the slider from the disk. However, because of the relative location of the slider and the limiter, the limiter in prior art is known to slide away from the load beam during high shock in the unloaded position. The limiter location also causes higher force to pull the slider off the disk.
Prior art also requires prebending of the limiter on the load beam before attachment of the flexure to the load beam. The steps required for this structure create difficulties in manufacturing.
It is desirable to design an integrated lead suspension assembly that overcomes the above-mentioned drawbacks.